APPLICATION SIGB

1. GENERAL CONSIDERATIONS

 

1.1. Designation
With the help of SIGB (former name NRS-1) it is possible to accomplish destruction of objects directly in acting shops, populated areas and so on and so forth with the complete safety for the environment since SIGBaction (former name NRS-1) is not accompanied by any fluctuations, ejection of solid or gaseous products.
 
1.2. Characteristics.
SIGB (former name NRS-1) is the powder-like material most frequently of gray color which forms dust. It is incombustible, no explosive and possesses:

• by alkalinity (pH-12.5);
• volumetric bulk density -1.2:1.3 t/m³;
• water-need - 28-30 %
• the developed pressure – up to 500 kgf/sm² (50 MPa).

Due to the increased SIGB (former name NRS-1) hygroscopic properties it is packed into the moisture resistance packing.
Guarantee period of storage (saving the air tightness of packing) in the dry placement is not less than 12 months.
 
1.3. Mechanism of action.
Mixing the powder SIGB (former name NRS-1) Mixing the powder SIGB (former name NRS-1) with water, the working mixture (suspension) is formed that being flooded into the partially or completely closed cavity (for example, bore-hole) in some object, gradually as a result of hydration reaction of the powder hardens increasing in the volume. The volume increase is accompanied by the pressure development on the walls of the containing cavity (bore-hole), its value in the course of time reaches 500 kgf/sm² (50 MPa). At that the stresses develop in the body containing the object. Value of stresses can exceed its maximum rigidity strength under tension that also will lead to the destruction of the object. The effect of destruction is expressed by formation of cracks and their development in the time in the body of the object (see fig. of appendix 1).
The use of present guidance must ensure the effective application of SIGB (former name NRS-1) as a result of:

• selection of the most rational diagram of conducting the work,
• reduction of the labor intensity,
• reduction of the manual labor expenditures due to the mechanization of works, of the labor intensity,
• increase of technological discipline.

 

2. ORDER OF CONDUCTING THE WORK

2.1. Process of destroying the object consists of the following technological operations:

• preparation of the object for the destruction (removal of the soil and rubbish, excavation, marking sections of destruction and so on),
• drilling bore-holes in accordance with the marking (diagram),
• preparation of the working mixture and filling bore-holes with it,
• destruction of the object (crack formation),
• development of objects (denudation and the subsequent cutting of armature, the removal of destroyed object parts from the zone of destruction).
• the most labor-consuming process in the complete set of works in essence determining the duration, the prime cost and the specific labor cost of the destruction of 1m3 of the object is drilling bore-holes.

2.2. ВPreparing the object for the destruction (for example, destruction of building constructions) the following points must be carried out:

• the inspection of the object,
• the study of working conditions of carrying out works taking into account the existing lift-transporting equipment,
• the development of the flow chart (regulations) of works,
• fully equipping, preparation and functional test of the necessary equipment,
• the instruction of personnel carrying out works.

2.3. As part of the flow chart to the destruction of the object the following characteristics enter:

• characteristic of the object of destruction (its sizes, volume, strength, openness, fracture, nature and the arrangement of armature) made according to the results of inspection to the existing documentation,
• the list of the necessary equipment,
• the diagram of boring bore-holes,
• indication in the technology of the preparation of the working mixture and sequence of its filling in bore-holes,
• safety features.

2.4. Development of the diagram of drilling bore-holes is based on the analysis:

• the characteristic of the object of destruction,
• the characteristic of the existing lifting-transporting equipment in the zone of destruction, tightness in the zone of destruction (presence of free surfaces in the object of destruction, non-for-liquidation objects, communication networks and so on).

2.5. Main characteristics of the destroying object considered in the development of the diagram of drilling bore-holes, are: ultimate strength in the break of the object material (destr.) and parameters of its reinforcement (for the steel concrete).
 
2.6. Distance between the bore-holes (step) can be tentatively determined using the following empirical formula:
L = 1000 * (α/σ), where
α – the diameter of the bore-hole (cm),,α
σ ultimate strength in the break of the object material, kgf/sm2.
Obtained according to the calculation value of the distance between bore-holes is refined in the process of conducting the preliminary tests ("trial destruction").
 
2.7. The basic principle in the design of drilling bore-holes diagram that ensures the greatest effectiveness of works is the rush to carry out, possibly, the smaller volume of drilling operations in connection with the concrete object. The volume of drilling operations will be the less, the less the overall sizes of the parts (blocks) will be that are formed in the destruction of the object. The latter depends, in whole, on the characteristics of the existing lifting-transporting equipment (see fig. 2 of appendix 1).
 
2.8. . Effective application of SIGB (former name NRS-1) requires the presence in the object at least two vertical free surfaces situated at a certain angle relative to each other (see fig. 3 of appendix 1). It must be formed in the absence of the second free vertical surface using traditional methods.

 
 

3. EQUIPMENT FOR DRILLING BORE-HOLES
3.1. Drilling bore-holes in the objects to be destructed is achieved mainly with the aid of the perforators, machine tools with the diamond circular drills can be used too. Crowns of different types are the working tool of perforators: chisel lamellar - CCL, cross lamellar - CCrL, chisel bolt – CCB, three-blade bolt – CTBB and etc. according to All-Union standard 17136 - 77. The characteristics of some perforators and crowns are given in the appendix.
3.2.In the great volume of drilling operations it is recommended to use the installations of row drilling.

 
 

4. BORE-HOLE DRILLING AND ITS PREPARATION
4.1. In whole it is recommended to drill bore-holes with the diameter of 32:42 mm. Using bore-holes with the diameter of more than 40 mm the probability of the spontaneous ejection of the working mixture from the bore-hole grows, especially, if the temperature of the object exceeds + 25 0C. The greater the diameter of the bore-hole is, the greater the destruction will be, but at that more SIGB (former name NRS-1)is expended.
4.2. If the object is characterized by the increased porosity, and therefore by water absorption, it is necessary to satiate bore-holes by water (before its filling with the working mixture).
4.3. The need for water saturation of bore-holes is determined as follows: The clean dry bore-hole (one or several depending on the size of the object) is completely flooded. If after 30 minutes from the moment of filling the water level in the bore-hole does not descend more than on 6 cm (taking into account 1 meter of bore-hole length), the saturation of bore-holes by water should not be done; otherwise all bore-holes are filled up with water during 30 minutes. After 30 minutes the water from bore-holes is moved away (for example, by compressed air) and filling with the working mixture is produced.
4.4.The depth of bore-holes depends on the height of the destroyed object, its cleavability, but in all cases it is less than its height by 5:10 cm. The direction of the appearing cracks (see fig. 5 of appendix) depends on the depth and the tendency of the object to the cleavage.
4.5. It is also possible to drill the horizontal and ascending bore-holes, but for filling them with the working mixture special attachments are required
4.6. The direction of the destruction is determined by arrangement of bore-holes in the object. Usually resultant cracks connect adjacent bore-holes or leave to the free surface of the object nearest from the bore-hole (see fig. 4 of appendix).
4.7.. In the destruction of the object with the height less than 30-40 cm, it is recommended to drill inclined bore-holes or to use bore-holes of the smaller diameter (see fig. 6 of appendix). It can be explained by the fact that the pressure created by the working mixture in the upper part of the bore-hole (equal to h = 3d) is less than in its lower part. The influence of the reduced pressure in the upper part of the bore-hole to the effect of destruction is the less, the more the depth of used bore-holes is.
4.8. The SIGB (former name NRS-1) expense for destroying the concrete object is determined on the basis of the fact that 1.8 g of powder SIGB (former name NRS-1), is required to fill 1 sm3 of the bore-hole, or using data of table.

The SIGB (former name NRS-1) expenditure on 1 metre of the bore-hole of different diameters
Diameter of bore-hole, mm	26	32	38	44
Expenditure SIGB (former name NRS-1), kg	0,95	1,50	2,00	2,70

4.9. For detecting the armature (if the diagram of the location of armature in the object is known) the drilling of bore-holes is made in immediate proximity of the armature (see fig. 7 appendix 1).
4.10. Arrangement of the nearest to the free surface bore-hole from the free surface must be two times less than the distance between the "internal" bore-holes (see fig. 5 of appendix 1).

 
 

5.PREPARATION OF THE WORKING MIXTURE AND FILLING BORE-HOLES WITH IT.
5.1. For preparation of the working mixture it is required:

• weights (for the weighting SIGB(former name NRS-1) portion),
• volumetric glass (for the dosage of water),
• vessel for mixing the powder with water (clean bucket or another vessel),
• mixer (with the large volume of works).

5.2. Preparation of the working mixture is accomplished as follows: In the clean vessel (for example bucket) the measured quantity of clean (tap) water is poured out, and then during the continuous mixing (by hand or mechanically) the weighed quantity of powder is gradually (!) poured out into the water and one continues to intermix till obtaining the mass of good fluidity without the visible lumps.
5.2.1. Thereat the ratio of water to the powder (throughout the mass) must be not more than 0.28g, i.e. on 1000g of powder it is necessary to take 280 ml. of water.
5.2.2. Time of mixing the mass must not exceed 8-10 min.
5.3. Bore-holes designed for filling with the working mixture must be clean, not contain dust, the fragments of material, water and so on.
5.4.The bore-holes are filled with the working mixture to the mouth. There is no need for stopping up the bore-holes filled with the working mixture by anything.
5.5.. If when filling the bore-hole the stratification of the working mixture (water-department) is observed, after 1-2 minutes of filling it is recommended to make the additional filling of the working mixture into already filled bore-holes for displacement of the separated water.
5.6. . After filling of the working mixture it is necessary to protect mouth of bore-holes from the action of water (for example, when it rains).
5.7. Application of SIGB (former name NRS-1) эффектиis effective, if the temperature of destroyed object is not less than +2+30C and not more than +250C. The higher the temperature of the object, the colder the water of tempering must be. FOR EXAMPLE: when the temperature of the object is +250C, the temperature of the water must be not more than 15-180C (otherwise the spontaneous ejection of the mixture from the bore-hole is possible), while the temperature of the object is +2+30C it is necessary to use hot (40-50 0C) water (otherwise the time of the destruction of the object increases).

 
 

6. CRACK FORMATION, EJECTION
6.1. Time of cracks formation (from the moment of bore-holes filling by the working mixture) in the destroyed object depends mainly on:

• the strength of the material of the object,
• the temperature of the object,
• the diameter of bore-holes,
• the distance between bore-holes,
• the liquid-water content in the working mixture,
• the temperature of the working mixture.

6.1.1. The higher ultimate strength in the break of the material of the object, the greater the time till crack formation is.
6.1.2. . The increase of the object temperature (in the indicated limits in unit 4) contributes to the acceleration oThe decrease of the distance between bore-holes accelerates the process of crack formation, but causes the increased expense of SIGB (former name NRS-1).
6.1.4. The increase of the liquid-water content in the working mixture contributes to retarding the process of crack formation.
6.2. Dispersion of water to the surface of the destroyed object in the zone of the formed cracks (zone moistening) contributes to the width increase.
6.3.Ejection of the working mixture from bore-holes can occur, if:

• the temperature of the destroyed object exceeds 300C,
• bore-hole diameter is more than 50 mm (at a normal temperature),
• the liquid-water content in the working mixture will be less than 0.25.

6.4. To decrease the ejection of the working mixture from bore-holes is possible using water with the lowest possible temperature for the preparation of the working mixture.

 
 

7. DEVELOPMENT OF THE OBJECT
7.1. After crack formation in the object for the baring of the armature in the zone of crack by pick hammer the groove (chase) is made, dimensions of which must provide the possibility of cutting the exposed armature (for example: by autogenous welder).
7.2. After cutting armature, object lumps (blocks) is removed from the zone of destruction with the help of the existing lifting-transporting equipment.
7.3.If the destroyed object is sunk into the soil, the latter must be removed (to excavate the object) considering the possibility of work performing on armature cutting and removal of the individual object parts.

 
 

8.SAFETY ENGINEERING.
The powder   SIGB (analog NRS-1) and the working mixture possess alkaline reaction that causes the need to work with safety engineering.
Working with SIGB (analog NRS-1) it is necessary to use goggles, respirator, and gloves. To wash off the working mixture, if it gets on the skin.
Not to glance into bore-holes flooded by the working mixture since the spontaneous ejection of the mixture is possible, especially working in the hot season.
Go to the doctor, if SIGB ((analog NRS-1) fell into the eyes.
To establish enclosures in the zone of the works and danger warnings.

 
 

For consultations regarding the use of SIGB (analog NRS-1) address:
140050, Moscow Region, Kraskovo, Karl Marks Street, 117. LLC "STROIMATERIALY"
Tel/fax: (495) 501-51-72 Sales department

Schematic figures.

Fig.1. Mechanism of SIGB (former name NRS-1) action

1 – the object of destruction, 2 - the bore-holes filled with the working mixture, 3 - free surfaces of the object, P - pressure in the bore-hole (crystallized pressure). ^ - tensile forces, 4 - cracks formed by the SIGB (former name NRS -1) action, a - the distance between bore-holes, b - distance from the center of the bore-hole to the free surface.

a. for the manual dismantling

b. for the dismantling with the use of lifting mechanisms

Fig. 2. Diagram of the destruction of objects in the absence (a) or presence (b) of lifting-transporting equipment

1 - bore-holes with the working mixture
2 - cracks formed by the SIGB action

Fig.3. Recommended diagram of blocks of mountain rocks output with two free vertical surfaces and by horizontal (inclined) nature crack

1 - vertical free surfaces;
2 - bore-holes with the working mixture; 3 – cracks formed by action SIGB (former name NRS-1)
4 - bore-holes prepared for filling with the working mixture;
5 - horizontal nature crack.

Fig. 4. Arrangement of bore-holes and directivity of the destruction

a. disorderly destruction
b. directed destruction

1 - bore-holes filled with the working mixture
2 – cracks

Fig. 5. Depth of bore-holes and crack formation

1 - free surface,
2 - bore-hole filled with the working mixture,
3 and 3 - cracks formed in the object (formation of crack 3 and crack 3' is determined by value and tendency of material toward the cleavage)

Fig.6. Destruction of objects of low height

a. use of bore-holes of smaller diameter or inclined bore-holes
b. change of the pressure (P) with change of the bore-hole depth

Fig. 7. Version of the arrangement of bore-holes with the destruction of reinforced concrete

a. use of bore-holes of smaller diameter or inclined bore-holes
b. change of the pressure (P) with change of the bore-hole depth